1. Field of the Invention
This application relates to medical devices. In particular, this application relates to endoluminal devices suitable for various medical applications and the methods for making and using such endoluminal devices.
2. Description of Related Art
The functional vessels of human and animal bodies, such as blood vessels and ducts, occasionally weaken. For example, an aortic wall may weaken, resulting in an aneurysm. Upon further exposure to hemodynamic forces, such an aneurysm may rupture, resulting in internal bleeding, and often, death.
The use of an endoluminal device or prosthesis, such as a stent graft is well known in the art as an intervention for repairing weakened, aneurysmal, dissected or ruptured vessels. An endoluminal prosthesis is delivered in a radially compressed configuration using a catheter delivery system. The catheter is introduced into the lumen system and the prosthesis is delivered to the repair site intraluminally. The prosthesis is then expanded to engage the luminal wall. The prosthesis provides some or all of the functionality of the original, healthy vessel and/or preserves any remaining vascular integrity by replacing a length of the existing vessel wall that contains the site of vessel weakness or failure. Endoluminal prostheses such as stent grafts may be used for the treatment of various functional vessels, including body lumens such as the esophagus, bile duct, or blood vessels.
Examples of stent grafts that may be used for treating damaged or diseased body lumens are described in PCT Application WO 98/53761, entitled “A Prosthesis and a Method and Means of Deploying a Prosthesis,” which is herein incorporated by reference.
Often times, a functional vessel may become damaged or defective at a branched location which includes a main lumen and at least one branch lumen extending from the main lumen. For example, an aneurysm may develop within the vasculature near the intersection between the abdominal aorta and branch vessels, such as the iliac, renal, celiac, and/or mesenteric arteries. Similarly, an aneurysm may develop near the intersection of the thoracic aorta and branch vessels, such as the innominate, left common carotid, and the left subclavian arteries. Repair of a damaged or defective branched vessel is particularly challenging because the stent graft must cover the entire affected area without occluding blood flow or obscuring access to adjacent lumens.
Various stent grafts have been provided for repairing main body lumens and spanning branch vessels without occluding fluid flow thereto. For example, a stent graft may be provided that has one or more fenestrations or apertures in the side wall of the stent graft. The stent graft may be deployed within a main vessel so that the fenestration is aligned with a branch vessel to allow fluid communication between the main vessel and the branch vessel.
In many cases, the vasculature is not symmetric. In addition, even with symmetrical vasculature, physiological forces may cause a previously placed stent graft to move causing the position of the fenestration to move with respect to the branch vessel. In other instances, where the disease extends into the branch vessel and affects the ostium of the branch vessel, a stent graft deployed within the main vessel may not properly seal and secure to the branch vessel and may lead to leaks (endoleaks) between the stent graft and the main vessel, reduced blood flow to the branch vessels, and/or may obscure access to portions of the branch vessel, necessitating further interventional procedures.
In cases such as these, a branch vessel prosthesis may be provided instead of or in addition to a main vessel prosthesis. For example, an abdominal aortic stent graft may be provided that extends over branch arteries such as the renal arteries, the celiac arteries, or the mesenteric arteries and that has one or more fenestrations that are alignable therewith. A branch vessel prosthesis may then be provided and attached to the abdominal aortic stent graft through a fenestration in the stent graft to complete the prosthesis.
United States Published Patent Application Nos. 2006/0058864, 2005/0222668, 2005/0171598, and 2005/0149166 A1 disclose various systems for repairing branched vessels, the disclosures of which are incorporated by reference here. Various aspects of each of these disclosures may be used in conjunction with the present invention.
Presently, the manufacture of stent grafts or covered stents requires specialized secondary procedures or specialized stent-attachment mechanisms. For example, the stent may be attached to a graft using external components such as hooks, sutures or other fasteners. Alternatively, a covered stent may be formed by using a dip-coating process to apply the graft to the stent. Such components and processes are both labor-intensive and costly.
Thus, there is a need for an endoluminal prosthesis that includes a stent and a graft where the stent and graft are secured together without the use of such attachment procedures or mechanisms.